1. Field of Invention
The invention relates generally to a flowmeter for measuring multiphase flow of wellbore fluids in a tubular. More specifically, the present invention relates to a flowmeter that heats a particular constituent in the flow stream electromagnetically and then measures the time delay until a temperature response is detected at some known distance downstream of the heating so as to estimate a flow velocity of that constituent.
2. Description of Prior Art
Flowmeters are often used for measuring flow of fluid produced from hydrocarbon producing wellbores. Flowmeters may be deployed downhole within a producing wellbore, a jumper or caisson used in conjunction with a subsea wellbore, or a production transmission line used in distributing the produced fluids. Monitoring fluid produced from a wellbore is useful in wellbore evaluation and to project production life of a well. In some instances transmission lines may include fluid produced from wells having different owners. Therefore proper accounting requires a flow measuring device that monitors the flow contribution from each owner.
The produced fluid may include water and/or gas mixed with liquid hydrocarbon. Knowing the water fraction is desirable to ensure adequate means are available for separating the water from the produced fluid. Additionally, the amount and presence of gas is another indicator of wellbore performance, and vapor mass flow impacts transmission requirements. Flowmeters can be employed that provide information regarding total flow, water cut amount, and gas fractions. However, these often require periodic analysis of the fluid entering the flowmeter. This may involve deploying a sample probe upstream of the flowmeter; which can produce inaccuracy, and may interrupt or temporarily halt fluid production.